The present disclosure relates to a laser marker (a laser level).
As a laser marker for use in civil engineering works, construction works, and so on, the one including a dry cell as a power supply is known. Such a laser marker generates laser lights by being supplied with electric power from the dry cell, and projects laser light reference lines onto a target object.
In a case where the dry cell, which is a non-rechargeable battery (a primary battery), is used as a power supply, when the dry cell is discharged to a certain level with the use of the laser marker, the dry cell needs to be replaced by a new one. Repetition of such replacement leads to increase in the number of discarded dry cells, and waste of resources might be thereby fostered.
To cope with this, as disclosed in U.S. Pat. No. 6,915,583 for example, a laser marker including a battery pack used as a rechargeable battery (a secondary battery), which is chargeable and dischargeable, is suggested instead of the dry cell. Such a chargeable and dischargeable battery pack can be reused by being charged, even when the battery pack is discharged with the user of the laser marker and becomes unable to supply electric power. That is, by using the chargeable and dischargeable battery pack as a power supply, waste of resources can be reduced compared to the case in which a non-rechargeable battery (dry cell) is used, because the battery pack can be reused by being charged.
In the above-described laser marker, as an attachment and detachment style of the battery pack, a style is adopted in which the battery pack is attached and detached by moving the battery pack in a direction perpendicular to an outer surface of the laser marker (hereinafter referred to as a push-in style).